With certain sensing probes as for example ultrasound probes, it often desirable to be able to take a biopsy of suspect tissue identified by the sensing probe. It is desirable that this biopsy be taken during the procedure which employs the sensing probe in order to use the sensing probe to locate and maintain the position of the suspect tissue and to guide the biopsy device relative to the suspect tissue so that appropriate tissue can be collected.
There are a number of ultrasound probes currently available on the market. These include probes having a stationary linear array of ultrasound transducers, probes having an end fire wobble-type transducer and probes having a side fire wobble-type transducer. The latter side fire wobble-type transducer probe is disclosed in U.S. Pat. No. 4,756,311, granted July 12, 1988 and assigned to Diasonics, Inc., the present assignee hereof.
With all of these types of probes, it is possible to secure thereto a biopsy guide for a biopsy needle with essentially provides for a straight in biopsy. This is to say, the biopsy attachment guides the biopsy needle straight in and parallel to but spaced from the probe itself. While this type of biopsy arrangement is satisfactory, for a biopsy in the rectal area a procedure is required whereby a perineal puncture is made in order to take a biopsy of tissue adjacent the rectal area. It is more satisfactory and a simpler procedure to be able to place the biopsy device in through the sphincter muscle so that perineal tissue need not be punctured.
With respect to an end fire probe or a linear array probe, it is possible to provide a passage through the ultrasound probe which is disposed at an angle to the length of the probe itself. Through this passage, a biopsy needle can be positioned after the probe is disposed in the rectal area. Such an arrangement is not possible with a wobble-type side fire ultrasound probe due to the mechanisms such as the motor and linkage arrangements as well as the transducer mounts which take a considerable amount of space immediately adjacent the transducer and prevent the incorporation of a guide passage adjacent thereto.
One solution to this problem which was only recently developed includes a biopsy guide which can be secured externally to the ultrasound probe and include a curved guide passage for directing and bending a biopsy needle. This curved guide passage is inserted through the sphincter muscle. The curved guide passage then allows a biopsy needle to be inserted through the sphincter muscle and then deflected away from the ultrasound probe in order to be positioned for a biopsy. Such biopsy attachments have not proven to be totally satisfactory in that the biopsy needles are generally not rated for bending and there can be very substantial friction between the biopsy needle and the guide tube as the guide tube forces the biopsy needle to be bent.